Neural correlates of auditory function and training in older adults

描述（由申请人提供）：许多老年人在背景噪音中感知语音时遇到过度困难。为什么这种情况会发生在一些人身上，而不是所有的老年人，这是一个目前没有答案的问题。我们的长期目标是了解老年人噪声中言语感知的生物学基础，并利用这些知识通过训练来改善感知。越来越多的证据表明，听觉系统（包括耳蜗力学和脑干）是动态的，可以通过短期（培训）和终身（语言和音乐）的经验来塑造。正常的语言交流依赖于神经系统对声音的准确转录，特别是在嘈杂的背景下。在老龄化人口中，这种转录过程的失败代表了巨大的社会和经济成本，并且相当多的资源被投入到可能不起作用的治疗中。在诊断和治疗方案的评价方面几乎没有客观的评估。此外，有新的证据表明，听觉外周是由更高的中心通过传出系统，以帮助在背景噪音听调制。这种贡献仍有待在人类物种中详细描述和/或量化。因此，我们的目标是确定脑干转录的语音声音在噪音中的老年人，这种转录与耳蜗力学的措施，和可塑性的转录与培训。我们的中心假设是转录准确性和耳蜗力学的破坏是噪音损伤的因素，并且可以通过干预来补救。这项工作的结果将揭示老年人在噪音中与言语感知相关的感觉机制，并确定短期训练产生的基本感觉回路的可塑性。这一结果将对我们理解和客观评估老年人的感觉功能产生积极影响。

DESCRIPTION (provided by applicant): Many older adults experience excessive difficulty perceiving speech in background noise. Why this occurs for some, but not all older individuals is a question that currently has no answer. Our long-term goal is to understand the biological bases of speech-in-noise perception in older adults and to use that knowledge to improve perception through training. Converging evidence indicates that the auditory sensory system (including cochlear mechanics and brainstem) is dynamic and can be shaped by short-term (training) and lifelong (language and music) experience. Normal verbal communication depends on the accurate transcription of sound by the nervous system, especially in noisy backgrounds. Failure of this transcription process in the aging population represents a huge social and financial cost, and considerable resources are invested in treatments that may not work. Little objective assessment exists in diagnosis and evaluation of treatment options. Further, there is emerging evidence that the auditory periphery is modulated by higher centers via the efferent system to aid listening in background noise. This contribution remains to be characterized and/or quantified in any detail in the human species. Accordingly, our objectives are to determine brainstem transcription of speech sounds in noise in older adults, how this transcription relates to measures of cochlear mechanics, and the plasticity of transcription with training. Our central hypothesis is that disruption of transcription accuracy and cochlear mechanics are factors in listening-in-noise impairments, and that disruption can be remedied by intervention. The outcome of the proposed work will reveal sensory mechanisms linked to speech perception in noise in older adults and determine plasticity of basic sensory circuitry arising from short-term training. This outcome will have a positive impact on our understanding and objective assessment of sensory function in aging adults.